prueba con esto
<td height="519" colspan="3" valign="top"><object width="555" height="500"><param name="movie" value="<?echo $row['swf_evento']; ?>"></param><param name="wmode" value="transparent"></param><embed src="<? echo $row['swf_evento']; ?>" type="application/x-shockwave-flash" wmode="transparent" width="555" height="500"></embed></object></td>
<td width="55"> </td>